Nuclear Medicine
Treatment Of Liver Cancer Wıth Microsphere Method
Liver cancer is a type of cancer commonly seen not only in our country but also in the USA and European countries. In the treatment of liver cancer, in addition to chemotherapy and drug treatments, successful results are also obtained with microspheres, one of the new generation applications. In liver cancer, due to its negligible side effects and advantageous features, it has attracted the attention of the medical community.
What Are The Characteristics Of Liver Cancer?
Liver cancers are examined in 2 main groups. The first is the group called primary cancers, which originate from the liver itself; the second is cancers of other organs that have metastasized to the liver. Primary liver cancers are those originating in the liver itself and are called hepatocellular carcinomas.
What Is The Difference Between The Microsphere Method And Other Methods?
The microsphere method is a specific treatment. Chemotherapy and drug applications, on the other hand, are systemic treatment methods, meaning they are not entirely targeted at the lesion in the liver. The fact that a treatment is specific means that systemic side effects will not occur, that is, there will be no debilitating side effects as seen after chemotherapy.
What is the incidence of liver cancer?
Worldwide, between 500,000 and 1 million new cases of primary liver cancer are seen each year. When looking at liver metastases, pancreatic and colon cancers stand out as the most common causes. Liver metastases occur in 50% to 70% of pancreatic and colon cancers, which is quite a high rate. Another striking statistic is that 20% of deaths in colon cancer are caused by liver metastases. For this reason, both primary and metastatic liver cancers have great clinical importance.
How is this treatment applied?
Microspheres are tiny beads measuring 20–50 microns, labeled with yttrium-90, a radioactive substance that emits beta radiation. The principle is to inject these yttrium-90-labeled microspheres into the arteries feeding the liver. This ensures that the drug given targets only the tumor tissues inside the liver.
Since it is retained in tumor tissues and blocks the capillaries that feed the tumor tissues, it is called the radioembolization treatment method. To reach the hepatic artery, a catheter is inserted through the femoral artery in the groin (similar to a cardiac angiography), and the drug is administered into the artery feeding the liver.
What are the treatment methods?
There are various treatment methods for liver cancers. The first method is surgical treatment, but surgery cannot be applied to every patient. This depends on the tumor content of the liver. If the tumor content of the liver is very high or there are multiple lesions, surgery cannot be performed in these patients. For patients who cannot undergo surgery, chemotherapy and specific drug therapies are other options. However, primary liver cancers are extremely resistant to treatment.
Since metastatic lesions are generally multiple, they do not respond well to these treatments. Therefore, in recent years, the radioembolization method has been used. In radioembolization, treatment is applied directly into the hepatic artery using 20–50 micron microspheres labeled with radioactive substances.
What are the advantages and disadvantages of the method?
The biggest advantage of the microsphere method is that it is not a systemic treatment and does not have the debilitating side effects seen in chemotherapy. A second advantage is that this treatment method can easily be applied to patient groups who have undergone chemotherapy, chemoembolization, or surgical treatment. In short, microspheres can be used in combination with other treatments. If the patient benefits from the treatment, it can be repeated.
Which patients can receive the microsphere method?
Since the primary target of this method is liver cancers, it is applied either to primary liver cancers or metastatic liver cancers. However, if the tumor burden—meaning the tumor has occupied a very high percentage of the liver (70%)—this method cannot be applied. Similarly, in cases of liver failure, the procedure cannot be performed. Which patient group can receive this method is determined based on preliminary tests.
How many patients have received this method and what is the success rate?
This method has been applied to many patients worldwide. In Turkey, it has been used widely for about 4–5 years. This specific method is applied in certain centers in our country. Approximately 200 patients per year have undergone this procedure, which corresponds to at least 1,000 patients to date in Turkey. However, it has been in widespread use for 10–15 years in the USA and European countries.
- Neuroendocrine tumors are tumors rich in somatostatin receptors (SSTr).
- Tumor groups with high SSTr content:
o Gastro-entero-pancreatic tumors (carcinoid, gastrinoma, insulinoma, glucagonoma, VIPoma)
o Sympatho-adrenal system tumors (pheochromocytoma, paraganglioma, neuroblastoma, ganglioneuroma)
o Medullary thyroid carcinoma
o Pituitary adenoma
o Merkel cell carcinoma
o Small cell lung carcinoma
o Breast carcinoma
o Melanoma
o Lymphoma
o Prostate carcinoma
o Non-small cell lung carcinoma
o Sarcoma
o Renal cell carcinoma
o Differentiated thyroid carcinoma
o Astrocytoma
o Meningioma
Somatostatın Receptor Imagıng With GA-68 DOTA PEPTIDE PET/CT In Neuroendocrine Tumors
With current conventional imaging methods, staging, restaging, and response evaluation of neuroendocrine tumors are very limited and have low sensitivity. Since neuroendocrine tumors have low glucose metabolism, FDG PET/CT also has low sensitivity. As Ga-68 DOTA Peptide PET/CT performs SSTr imaging, this method demonstrates the SSTr content of the neuroendocrine tumor with high molecular sensitivity.
GA-68 DOTA PEPTIDE PET/CT Indications
- Detection of primary tumor location and metastatic sites (staging)
- Detection of residual, recurrent, or progressive disease (restaging)
- Determination of Lu-177 therapy indication based on Ga-68 peptide uptake in metastatic disease
- Assessment of treatment response (surgery, radiotherapy, chemotherapy, or Lu-177 peptide therapy)
Precautions Before Or After Imaging
The test is strictly contraindicated in pregnant women. Technically, Ga-68 DOTA Peptide PET/CT is similar to FDG PET/CT; the only difference between the two methods is the radiopharmaceutical used.
Treatment With Lutetium (Lu) 177 Peptide In Neuroendocrine Tumors
Since Lu-177 is a radionuclide emitting beta radiation, the distance it travels in tissue is between 1–3 mm. With this property, it provides a specific and internal radiotherapy opportunity. Lesions that appear positive on Ga-68 DOTA Peptide PET/CT will also show uptake of Lu-177-labeled peptides.
Indication
Lu-177 peptide therapy is indicated for all inoperable and/or metastatic neuroendocrine tumors with positive SSTr content on Ga-68 DOTA Peptide PET/CT imaging.
Method of administration
The Lu-177-labeled peptide is diluted in isotonic solution (10–100 ml) and administered intravenously over 10–20 minutes. For radiation safety, the patient stays at least 1 day in a single room specially licensed by TAEK. Treatment cycles are generally carried out in 4–5 sessions at 6–8 week intervals.
Side Effects
- Acute: Nausea, vomiting, abdominal pain
- Kidney Toxicity: Reduced as much as possible with kidney-protective applications
- Bone marrow Toxicity: Reversible in 2–5% of patients, especially those with extensive bone metastases
Treatment Effectiveness
Lu-177 peptide therapy has been used worldwide for about 10 years and in certain centers in Turkey for about 3 years. Literature data show that Lu-177 peptide therapy contributes to prolonged survival, symptom improvement, improvement in biochemical markers, and better quality of life in SSTr-positive neuroendocrine tumor patients.
Gallıum (Ga) 68 PSMA PET In Prostate Cancer
Prostate cancer is the second most common cancer in men and ranks sixth among causes of cancer death. As with all cancers, determining the appropriate treatment method at the right time is very important in prostate cancer.
Recently, determining the extent of disease (metastases) in prostate cancer by whole-body scanning has become possible with a method called Gallium-68 PSMA PET. PSMA is a substance specific to the prostate. With Gallium-68 PET imaging using this substance, uptake is detected only in regions where prostate cancer is present.
By determining the status of the disease with Gallium-68 PSMA PET, it becomes possible to select the most appropriate treatment method.
Actinium-225 Dota Therapy In Neuroendocrine Tumors
Actinium-225 (Ac-225) is a radionuclide that emits alpha particles. The energy of alpha-emitting radioactive substances is much higher than other types of radiation. Therefore, the energy levels they produce in biological tissues are also very high, and the distances they travel within the tissue are very short. For these reasons, alpha-emitting radioactive substances have very specific properties in treatment applications.
Ac-225 DOTA therapy is a radiopharmaceutical used in neuroendocrine tumors. Since classical chemotherapies are not used in most neuroendocrine tumors, Ac-225 DOTA therapy is an important treatment option for this patient group. This therapy is especially preferred in patients who do not benefit from beta radiation therapy applications (Lutetium-177 DOTA).
Before Ac-225 DOTA therapy, Ga-68 DOTA PET/CT imaging must be performed, showing intense radioactive uptake.
Ac-225 DOTA therapy is administered intravenously at 6–8 week intervals. After administration, Ac-225 DOTA is retained in tissues containing active neuroendocrine cancers (somatostatin receptors) throughout the body, destroying cancer cells with alpha radiation. Hospitalization is not required after treatment, and patients are discharged the same day. The number of treatments depends on the treatment response, which is evaluated by Ga-68 DOTA PET/CT imaging and some laboratory tests.
ACTINIUM-225 PSMA Therapy In Treatment-Resıstant Prostate Cancers
Ac-225 PSMA therapy is a radiopharmaceutical used in prostate cancers that progress despite standard treatments and are resistant to them. It is also preferred in patients who do not benefit from beta radiation therapy (Lutetium-177 PSMA).
Before Ac-225 PSMA therapy, Ga-68 PSMA PET/CT imaging must be performed, showing intense PSMA uptake.
Ac-225 PSMA therapy is administered intravenously at 6–8 week intervals. After administration, Ac-225 PSMA is retained in tissues containing active prostate cancer throughout the body, destroying cancer cells with alpha radiation. Hospitalization is not required after treatment, and patients are discharged the same day. The number of treatments depends on the treatment response, which is evaluated by Ga-68 PSMA PET/CT imaging and changes in serum PSA levels.
Paın-Relief Treatment For Bone Metastases (EDTMP Lu-177)
Bone metastases can develop in many cancers, especially prostate, breast, lung, and kidney cancers. The most important factor negatively affecting patient comfort in bone metastases is pain.
There are many methods used for pain treatment, but they are often insufficient in preventing pain. Radionuclide therapy for bone metastases has been widely used worldwide for many years. Recently, Lu-177 EDTMP has been used in the treatment of painful bone metastases.
Lu-177 is a beta-emitting isotope with therapeutic properties. When EDTMP, which has an affinity for bone tissue, is labeled with Lu-177 and administered intravenously, the radioactive substance accumulates intensely in all active bone metastases. This allows beta radiation to treat bone metastatic sites and eliminate pain caused by nerve compression.
Before this treatment, a standard bone scintigraphy should be performed. The decision for treatment is made based on the bone scintigraphy results.
A rare side effect of Lu-177 EDTMP therapy in patients with extensive bone metastases is bone marrow suppression, resulting in a decrease in blood cells (red cells, white cells, platelets). Therefore, a complete blood count is recommended before treatment for all patients and post-treatment in at-risk patient groups.
Lu-177 EDTMP therapy can be repeated every 2–3 months depending on the treatment response.
For detailed information and a second opinion about the Lu-177 EDMP application for patients with bone metastases in our Nuclear Medicine clinic, you can contact us.
